Display panel having memory

ABSTRACT

A display panel includes a plurality of layers of gas-filled glow cells and a plurality of arrays of electrodes. One layer of cells is scanned once for each picture to be stored and displayed, and another layer is used to display the glow or picture with memory.

[ Nov. 18, 1975 United States atent 1191 Glaser et al.

[51] Int.

[ DISPLAY PANEL HAVING MEMORY A47B 43/00; HOSB 37/00 [58] Field of Search... 313/188; 315/169 TV, 169 R Inventors: David Glaser, Green Brook; George A. Kupsky, Milford, both of NJ. References Cited [73] Assignee: Burroughs Corporation, Detroit, UNITED STATES PATENTS 315/169 TV 315/169 R Mich.

Mar. 12, 1974 [22] Filed:

Appl. No.: 450,535

Related US. Application Data [63] Continuation of Ser. No. 293,384, Sept. 29, 1972,

which is a continuation of Ser. No. 38,409, May 18, 5 'm?' f h] 1970, abandoned. SSlS an .rammerawrence a Attorney, Agent, or FirmKenneth L. Miller; Robert A. Green [30] Foreign Application Priority Data May 4, 1971 ABSTRACT A display panel includes a plurality of layers of gasfilled glow cells and a plurality of arrays of electrodes. 7106719 One layer of cells is scanned once for each picture to 17995 be stored and displayed, and another layer is used to display the glow or picture with memory.

Canada................................ May 4, 1971 United Kingdom.... May 13, 1971 Germany................ May 17, 1971 Japan............. May.17, 1971 Netherlands....... May 18, 1971 France..............................

[52] US. Cl. 313/188; 315/169 TV 29 Claims, 16 Drawing Figures us. Patent Nov. 18,1975 sheetlofs 3,921,021"

INVENTOR. DClVId Glaser George A. Kupsky ATTORNEY Sheet 2 of 8 US. Patent Nov. 18, 1975 7O 34 'lO7 70 7 1 Fig.3

INVENTOR. David Glaser George A. Kupsky ATTORNEY U.S. Patent Nov. 18, 1975 Sheet5of8 3,921,021

INVENTOR. David Glaser George A. Kupsky ATTORNEY US. Patent Nov. 18, 1975 Sheet6of8 3,921,021

INVENTOR. DClVld Glaser George A. Kupsky ATTORNEY US. Patent Nov. 18, 1975 shet vofs 3,921,021

A1X27Y4 Fi .12 I Fig.13

to I35 F 9-1 Dovwwa' er 3 George A. Kupsky ATTORNEY DISPLAY PANEL HAVING MEMORY This a continuation of application Ser. No. 293,384, filed Sept. 29, 1972, which is a continuation of Ser. No. 38,409, filed May 18, 1970 (now abandoned).

BACKGROUND OF THE INVENTION Display panels comprising a plurality of gas-filled cells, which can be turned on by the application of anode and cathode firing voltages to selected cells to display a message, are known in the art. Generally, such devices require that the information-containing firing voltages be applied as long as cells are to be held ON and the message is to be displayed. Such devices and cells, by definition, do not have memory. Again by definition, panels and cells have memory if they can display a message after the information-containing firing voltages have terminated or, in a more limited sense, if different voltages not having the information content of firing voltages can be used to maintain the message display. The present invention provides a unique display panel construction which can be operated with memory.

SUMMARY OF THE INVENTION Briefly, according to the invention, a display panel includes a plurality of layers of cells and electrodes, one layer and one group of electrodes being adapted to be scanned, while the others can be used to store and display a pattern of glow representing the input of information to the panel.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of a display panel embodying the invention and showing alternative electrode arrangements;

FIG. 2 is a sectional view along a row of cells showing one form of the panel of FIG. 1 when assembled;

FIG. 3 is a view similar to that of FIG. 2 including a different array of electrodes;

FIG. 4 is a sectional view along a column of cells in the panel shown in FIG. 2;

FIG. 5 is a schematic representation of a portion of the panel of FIG. 1 and a portion of a circuit with which it may be operated to scan the scanning cells;

FIG. 6 is a schematic representation of the entire panel of FIG. 1 and another portion of a circuit with which it may be utilized to operate the display cells of the panel;

FIG. 7 is a schematic representation of one of the modification panels of FIG. 1 and a circuit with which it may be utilized to operate the scanning cells and display cells of the panel;

FIG. 8 is an exploded perspective view of another form of display panel embodying the invention and permissible electrode modifications therein;

FIG. 9 is a sectional view along a row of cells showing one form of the panel of FIG. 8 assembled;

FIG. 10 is a schematic representation of a portion of a panel shown in FIG. 8 and a circuit with which it may be operated with memory;

FIG. 11 is an exploded perspective view of another type of panel with which the principles of the invention may be employed;

FIG. 12 is a schematic representation of a plan view of the panel of FIG. 11 showing the type of character display provided thereby;

FIG. 13 is a schematic representation of the manner in which characters are formed by the panel of FIG. 11; FIG. 14 is a schematic representation of the panel of FIG. 11 and a circuit with which it may be operated;

FIG. 15 is an elevational view, partly in section, of a modification of the invention; and

FIG. 16 is an elevational view, partly in section, of another modification of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The display panels described herein are thin, flat, sheet-like members which may have substantially any desired size and shape from, for example, postage stamp size to wall size, and they may include substantially any number of display cells. The panels may also include any suitable ionizable gas such as neon, argon, zenon, etc., singly or in combination, with a vapor of a metal such as mercury usually included in the gas to minimize cathode sputtering. The gas used is preferably a Penning mixture in which the gases of the mixture have related energy levels such that the metastable atoms of one gas produce ions of the other gas. Neon and xenon comprise a particularly effective Penning mixture. The gas pressure is preferably between 100 to 250 Torr, and, more particularly, about 175 Torr.

A display panel 10 embodying the invention (FIGS. 1 to 4) includes a first insulating base plate 20 of glass, ceramic, or the like having a plurality of parallel slots or channels formed in the top surface thereof. The slots 30 may have any suitable cross-section, and, for purposes of description, they are considered to be oriented horizontally. A second group of vertical slots 34 are also formed in the top surface 40, and these interconnect horizontal slots 30. Not all of the slots 34 which are shown are required in one mode of panel operation described below (see FIG. 5), and none is required in a second mode of operation described (see FIG. 7).

Electrodes 60, preferably wires used as scanning anodes in one mode of operation, are seated in slots 30, and electrodes 70, used as scanning cathodes, are seated on or in the top surface 40 of plate 20. The cathode electrodes 70 are preferably flat strips, and each has a series of holes or apertures 74. The cathodes are oriented vertically, parallel to each other, overlaying vertical slots 34 (if provided), and they are oriented at an angle, preferably 90, to the anode electrodes 60, so that each cathode electrode 70 crosses each anode electrode and each crossing defines a scanning cell 80. A cathode aperture 74 is located at each electrode crossing and at each cell 80. Each cathode thus lies along a column of cells 80, and each anode 60 lies along a row of cells 80. In addition, each column of cathode apertures lies along a column of cells 80, and each row of cathode apertures, defined by the array of cathodes, lies along a row of cells 80. Thus, each scanning cell is made up of a portion of an anode 60, the associated portion of cathode 70 above it, and the volume of gas in slot 30 between these electrode portions.

A second insulating plate 110, of glass, ceramic, or the like and having a plurality of apertures of cells arrayed in rows and columns, is seated on the electrodes 70 and the top surface of plate 20, with each aperture of cell l20 aligned with a cathode aperture 74 and with a cell 80 beneath it. Electrodes 70 might be seated in slots (not shown) in the bottom surface of plate 110, if desired.

It is to be noted that the cells 80 are in a first layer. and cells 120 are in a second layer above the layer of cells 80, and the rows and columns of cells 120 are generally aligned with, or at least in gas communication with, the rows and columns of scanning cells 80, with each cell 120 positioned above a cell 80.

Third electrode means in the form of a thin metal plate 130 (FIGS. I and 2) having apertures 140 in rows and columns is seated on insulating plate 110. The metal plate 130 has its apertures each generally aligned with, or in gas communication with, one of the apertures 120 in plate 110.

Alternatively, the third electrode means may comprise a plurality of strip electrodes 13h, each overlaying a row of cells 140 and each having a row of apertures 133, each of which overlays a cell 140. The electrode strips 131 are parallel to the electrodes 60 in plate 20.

Another apertured insulating plate 160, similar to plate 110 and having similar arrays of rows and columns of holes or cells 170 aligned with, or in gas communication with, cells 140, is seated on electrode plate 130. The cells 170 are used as display cells.

Fourth electrode means is provided between plate 160 and the panel viewing cover plate 190. This fourth electrode means may comprise a thin, transparent film electrode I80 (FIGS. 1 and 2) of tin oxide, gold, or the like, formed on the bottom surface of the glass cover plate 190 of the panel and having a terminal 210 suitably secured thereto.

In an alternative arrangement (FIGS. 1 and 3), the fourth electrode means comprises small diameter parallel wires 212, each oriented horizontally overlaying a row of cells I70 or vertically overlaying a column of cells 170. The electrodes 212 are normally connected together to a common terminal 214 and are operated as a unit, and they are of suitably small diameter so that they do not obscure glow in cells 170. The fourth electrode means might also comprise an apertured metal plate similar to plate 130.

It can be seen that a vertical flow path or gas communication path is provided from each bottom scanning coil 80 to each upper display cell 170 through the holes 74 in electrodes 70, the holes or cells 120 in plate 110, and the holes 140 in plate 130.

The various insulating plates and electrodes of panel I are secured together along their adjacent edges by a seal 200 formed of a glass frit or the like, shown in FIGS. 2, 3', and 4. The various electrodes, of course, are also secured in this seal area and project beyond the seal so that connections can be made thereto. In addition, the panel is filled with gas through a tubulation 203 secured to plate (FIG. 2) or in any other suitable fashion.

In the description of the operation of the invention set forth below. reference is made to scanning' or glow transfer" from cell to cell. These terms are applied to several different types of actions including glow transfer from a scanning cell to a scanning cell. and from a scanning cell to a display cell. The exact mechanism by which each such action occurs cannot be described with complete certainity. The actions may involve l actual transfer of a mass of glowing ionized gas, or (2) the diffusion of excited particles including metastable states which prime and adjacent OFF cell and thus facilitate the firing thereof, or (3) both mechanisms may be involved.

In operating a display panel, it may be desirable to provide a source of excited particles, such as electrons or the like, to facilitate the firing of gas cells, for example, at the beginning of a scanning operation. Such a source may comprise an auxiliary gas cell, known as a keep-alive cell, suitably located in the panel and ON continually to act as a constant source of excited particles. Various arrangements of keep-alive cells are shown and described in some of the applications referred to herein, and one such cell 220 is illustrated schematically in FIG. 5, which is a schematic representation of a portion of panel 10 and a circuit with which a portion thereof may be operated.

Display panels embodying the invention are operated generally in a manner described and claimed in copending application Ser. No. 850,984, filed on Aug. 18, 1969 as a continuation-in-part of application Ser. No. 828,793, filed May 28, I969. Briefly, in this mode of operation, the scanning cells are fired and turned on cyclically and continually, and, as the scanning cells are turned on, the corresponding associated display cells can be turned on, by transfer of glow from the scanning cell to the display cell, in response to information control signals applied to the panel electrodes. The resultant total number of display cells, which are turned on, display the character or message contained in the information control signals.

Considering the operation of the scanning cells 80, it is desirable to turn on or scan these cells in some regular routine, with the preferred methods being either cell by cell and row by row in raster fashion or column by column beginning, say, at the left-hand edge of the panel and proceeding to the right-hand end. As is well known, each scanning cell 80 can be turned on by applying operating potentials to the anode and cathode which cross at the cell. Various arrangements for operating scanning cells are set forth in application Ser. No. 850,984, application Ser. No. 881,660, filed Dec. 3, 1969, and in an application of Glaser and Kupsky entitled DISPLAY PANEL WITH RASTER SCANNING MEANS and filed concurrently herewith.

A typical scanning operation is now described with respect to FIG. 5 in which the scanning anodes are numbered 60A, B, C, D, E, and the scanning cathodes are numbered 70A, B, C, D, and the scanning cells are numbered AA, 80AB, etc., with the first letter being the letter associated with the cell anode, and the second letter being the letter associated with the cell cathode. The block connected to each electrode, 61 to each anode and 71 to each cathode, represents the required source of operating potential, and the various blocks can be operated synchronously by means of appropriate eircuits (not shown), as required.

In one mode of operation of the panel 10, the scanning cells 80 are scanned, that is turned on, one at a time in raster-type fashion, beginning with, say. the first cell 80AA at the upper left-hand corner of the plate 20, and the scanning operation proceeds from cell to cell along the top row to the right-hand end, from which it proceeds directly vertically to the next adjacent or second row and to the last cell therein, from which it proceeds to the left along the second row to the first cell at the end of the second row and then downwardly to the first cell in the third row. and from there to the end ofthc third row, and so forth, to the last cell in the plate 20.

In more specific terms, the above-described scanning operation is carried out by applying a generally positive operating potential to anode A and by applying a generally negative operating potential to cathode A. so that cell AA tires and turns on. Next, the second cathode 708 has operating potential applied to it while operating potential is removed from the first cathode 70A. Now, the second cell in the first row, cell SOAB turns on, and cell 80AA turns off. This switiching of the cathode operating potential is carried out until the glow reaches the last cell 80AD in the first row. This transfer of glow along the first row of cells is facilitated by the common horizontal slot 30, in which these cells are located and by the diffusion of excited particles therein. With the last cathode 70D still carrying its operating potential, positive operating potential is applied to the second anode 60B associated with the second row of scanning cells, and. at the same time, operating potential is removed from anode 60A. Thiscauses the glow to transfer from the last cell in the first row to the adjacent last cell in the second row. This operation is facilitated by the presence of a vertical slot 34 between those last cells in the first and second rows and by the diffusion of cxicted particles therein.

Now, with the operating potential again applied to each of the cathodes in turn, but in the reverse order beginning at the right-hand end and proceeding to the left-hand end of the panel, the glow is transferred by means of slot 30 toward the left along the second row of cells 80. When the glow reaches the last cell at the left-hand end of the second row, operating potential is switched from anode 608 to anode 60C, and the glow transfers through the associated slot 34 to the first cell 80C A in the third row of cells. The scanning operation is now again carried out to the right along the third row.

In this way, the scanning operation is carried out cell by cell and row by row through all of the cells 80 in the lower portion of the panel.

It is noted that the mechanical and electrical parameters of the scanning operation are selected to cause glow in the scanning cells to remain in these cells during the scanning operation. That is, the glow does not move upwardly by itself into the cells above the scanning cells. These parameters include the size of the scanning cells, the size of the apertures in the scanning cathodes which should be about 1 to 3 mils in diameter, the current density which should be held at a suitable level in conjunction with the cathode aperture size and cell size, etc. However, the glow in the scanning cells generates excited particles such as electrons, metastable states and the like which diffuse through the cathode apertures and prime the adjacent upper cells for a subsequent glow transfer operation,

As described above, each scanning cell 80 has an associated display cell 170 disposed above it. According to the invention. display cells associated with scanning cells can be fired and caused to glow and the glow can be sustained as follows. Referring to FIG. 6 which is a schematic representation of the panel 10 and its electrodes and a portion of an operating circuit, a source 230 of pulses 232 is connected between transparent electrode 130, with appropriate switch means 233 being provided to operate source 230. Sustaining pulses 232 are applied continually from the source 230 during operation of the panel and during the scanning operation. The amplitude. ,width, and frequency of pulses 232 are such that these pulses by themselves will not cause glow to transfer from scanning cells 80 to display cells 170. In addition, a source 237 of control data or information signals is connected through a suitable switching circuit 235 to the electrode plate 130. Source 237 and circuit 235 are used to apply glow transfer or write' pulses to the panel. These are generally positive pulses.

If, as each of the scanning cells 80 is turned on and with sustaining pulses 232 being applied constantly, at some instant a write pulse is applied from source 237 to plate 130; then, with the aid of excited particles from the scanning cell 80 which is ON at that instant. glow is transferred up into the associated display cell 170 where it is sustained by the sustaining pulses 232 after the write pulse has been removed and circuits 237 and 235 have been switched OFF. If this operation is performed for a plurality of the scanning cells as each is fired, then a picture or message can be displayed and stored in the display cells 170.

It is believed that the above-described glow transfer operation occurs as follows. When a scanning cell is fired, excited particles from the glow diffuse through the associated cathode aperture into the adjacent associated cell which is primed thereby. In general, these excited particles do not diffuse into cells 170 so that the sustaining pulses 232 by themselves do not fire the cells 170. When a write pulse is applied to electrode 130, the associated primed cell 120 fires and excited particles therefrom now diffuse into and prime the associated cell 170, and. at this time, the sustaining pulses can fire cell 170. In effect, cells 120 act as buffers or screens between scanning cells 80 and display cells 170. It is noted that this operation occurs at such high speed that the intermediate firing of cells I20 is not visible as a separate occurrence. This theory of operation also applies to other display panels described herein.

When desired, the displayed and stored picture can be cleared or erased by discontinuing the sustaining pulses 232 from between electrodes 180 and for a suitable period of time. Another picture or message can then be established and stored in the panel by carrying out the scanning and storing operation described above.

In another mode of operation, when strip electrodes 131 are used in place of the plate electrode 130 as shown in FIG. 7, the panel may be selectively erased by disconnecting the sustaining source 230 from selected electrodes 131 and thus from rows of cells and permitting new information to be inserted into the corresponding scanning cells 80. As the corresponding row or rows of scanning cells are fired again and with the sustaining source re-connected, new control signals from data source 137 transfer glow into selected cells in the erased rows so that a new character or message is now entered and stored in the display cells. This selective erasing technique can also be employed with the panel and system shown in FIG. ll) described below,

It is to be noted that data source 237 (FIG. 6) and write circuit 235 may also be connected to electrode so that the write pulse can be applied thereto instead of to electrode I30. However, this is not an optimum arrangement for the panel structure described.

In the foregoing mode of operation, the sustaining pulses 232 have such amplitude, width. and frequency that they cannot by themselves cause display cells to fire. However, once a cell 170 has been fired. as described above, each pulse re-fires the cell by utilizing excited particles which persist for a time after each firing. If the pulses fire the cell or cells at a suitable repetition rate, the cell appears to the eye to be ON continually.

In the foregoing mode of operation, electrodes 131 can be connected together and used in place of plate 130, and electrodes 212 can be used in place of electrode 180.

A display panel, which includes separate electrodes 131 rather than plate 130, can be operated somewhat differently by scanning column by column rather than cell by cell. Portions of such a panel and some associated circuit elements are illustrated in FIG. 7. In this mode of operation, all of the scanning anodes 60 are connected together to a common source of operating potential 63. The scanning cathodes 70 are connected as in FIG. 5, and the electrodes 131 are connected to switching circuits 135A to D so that each can be energized individually by means of control signals from data signal source 137. With this arrangement, each electrode 131 can be energized separately. Pulse source 230 is connected between electrode 180 and each of the circuits 135 as shown whereby pulses 232 can be applied between electrode 180 and electrodes 131.

In operation of the panel and circuit shown in FIG. 7, with sustaining pulses 232 applied constantly, scanning cells 80 are scanned, or turned ON, column by column, by means of generally positive potential being applied at the same time to all of the anode electrodes 60 and with generally negative operating potential being applied to each of the cathode electrodes 70 in turn. As each cathode electrode is energized, the column of cells 80 associated therewith is fired, and, if, as each column of cells is fired, information control signals from source 137 are applied to the sources 135 so that write pulses are selectively applied to electrodes 131, then the associated corresponding cell 170 in the column is caused to fire and glow. When this procedure has been carried out for each column of cells, a completed picture or message is displayed in the cells 170 to which glow has been transferred. This picture or message can be sustained by the constant application of sustaining pulses 232 from source 230 connected between electrode 180 (or 212) and each source 135 and thus each electrode 131, as described above with respect to FIG. 6.

It is noted that, in this mode of operation, slots 34 are not required.

It is also to be noted that the panel can be operated, without memory, to display a character or message, in the manner described in application Ser. No. 850,984, by scanning cells 80 continually and turning ON the desired associated display cells 170 by applying firing or write pulses to electrode 180 alone or to both electrodes 180 and 130 at the proper instant in the scanning cycle. By carrying out these operations at a suitable repetition rate, a stationary but changeable message can be displayed.

A modified panel 10', shown in FIGS. 8 and 9, includes all of the elements of the panel 10 described above, but, in addition, it includes a transparent or translucent insulating sheet or plate 240 of glass or the like between apertured plate 160 and the abovedescribed fourth electrode means. either conductive film 180 or electrodes 212, preferably film 180. The plate 240 is preferably of glass which has a high dielectric constant (at least 5), and it also preferably has a thickness of about 1 mil. The plate 240 may actually be a thin plate of glass, or it may be a thin layer of a glass frit deposited on the conductive film 180 and fired to cause it to bond to face plate 190.

The provision of glass plate 240 in panel 10 insulates electrode 180 from the gas in display cells 170 and has it capacitively coupled thereto and permits memory to be achieved in the glow in cells 170 by the application of a sinusoidal A. C. signal between electrode 180 and either plate 130 or electrodes 131.

One suitable circuit arrangement for achieving this A. C. memory operation is similar to that described with respect to FIG. 7 and is shown schematically in FIG. 10 in which panel 10 is shown schematically and is represented by electrode 180 and four electrodes 131. The circuit shown in FIG. 10 includes A. C. signal source 250 coupled to electrode 180 and through separate resistive paths 260 to each electrode 131. Circuits 137 and 135 described above are also capacitively coupled to each electrode 131 as shown. The scanning anodes and cathodes are connected as described and as shown, for example, in FIG. 7.

In operation of this circuit, the A. C. signal from source 250 is applied continually between electrodes 180 and 131 and, as described with respect to FIG. 7, glow is transferred from the scanning cells to display cells 170 by means of appropriate write signals applied to electrodes 131 from source 137. After glow has been transferred to the display cells, it is sustained in the display cells by the A. C. signal from source 250. When desired, glow in the display cells can be removed or erased by turning off A. C. source 250 or by opening all of selected ones of the switches shown in the resistive paths 260.

Typically, in FIG. 10, the scanning anodes are connected through a resistive path to a power source of +250 volts, and the scanning cathodes are at ground when ON and at about volts when OFF. The electrodes or 131 are at about 80 volts when OFF and at about volts when a write pulse is applied and when glow is transferred. The AC. source 250 provides a sinusoidal signal of about 450 volts peak-to-peak at a frequency of about 500 cycles to about 7 kc.

As noted, the AC. signal from source 250 itself has insufficient energy to fire display cells. However, once a display cell has been fired, the sinusoidal signal utilizes the excited particles and charges built up on the walls of the cell, which persist for a time after the cell fires, to re-fire the cell on each half cycle. The frequency of the signal is sufficient to properly re-fire the cell at such a rate that display appears to be stationary.

The principles of this invention may also be utilized to operate a panel of the type described and claimed in copending U.S. patent application Ser. No. 21,125, filed Mar. 19, 1970. This type of display panel 300 is illustrated schematically in FIGS. 11 and 12 and is constructed to display a plurality of rows or registers of characters as shown in FIG. 12. Substantially any number of registers and any number of characters per register may be displayed. Panel 300 is constructed so that each character area in a register includes at least 25 cells in a rectangular area having five cells on a side, and each character is formed by lighting the properly positioned cells. As described, each cell is formed at a crossing of two electrodes so that each character area also includes five vertical electrodes and five horizontal electrodes. The electrode arrays and typical characters which can be formed in two registers are illustrated in FIG. 13.

Panel 300 includes a bottom plate 310 which has a plurality of parallel horizontal slots 320 in which scanning anode wires 330 are seated. As noted, in actual construction, the plate 310 includes at least five slots and five scanning anodes for each register with a suitable interregister space provided between each group of slots and anodes. For convenience, only three slots are shown in FIG. 11 for each register, and only three registers are shown. On the top surface of plate 310 are seated a plurality of scanning cathode electrodes 340 which are strip electrodes having a series of apertures 350 positioned over slots 320, the cathodes being oriented at 90 to the scanning anodes so that each cathode crosses each anode and each crossing occurs over a slot and defines a scanning cell. A cathode aperture 350 is located at each such cell. Again as noted above, at least five scanning cathodes are provided for each five scanning anodes to form a character area, and a space may be provided between each five cathodes, if desired. For convenience, only three cathodes per character and three groups of cathodes per register are shown in FIG. 11. This arrangement permits the display of three registers of three characters each.

An insulating plate .360 is seated on plate 310 with the cathodes 340 between the two plates. The plate 360 has an aperture 370 for each cathode aperture 350; thus, the apertures 370 are arranged in three groups, one for each register of characters. An apertured electrode or wire 380 is seated on plate 360, each aligned with a row of apertures 370 therein, and another apertured insulating plate 390 similar to plate 360 is seated thereon. Plate 390 has an aperture or cell 400 for each aperture 370 in plate 360.

Finally, the panel 300 includes, in order, a transparent insulating plate 410, three transparent electrodes 420, and a transparent or translucent cover viewing plate 430. Plate 410 preferably is of glass or the like and has a high dielectric constant, and the electrodes 420 may be transparent gold or NESA films or the like secured to either plate 410 or 430 and provided with suitable contact leads 440. The electrode films 430 are rectangular in area, and each overlays and controls the operation of the display cells 400 in an entire character register in a manner to be described. Top plate 430 is also preferably of glass.

In operation of panel 300, referring to FIG. 14, the scanning cells in plate 310 are scanned column by column as described above with respect to FIG. 7, and selected display cells 170 are fired in accordance with singal information applied to electrodes 380 from the appropriate write source 137. These fired cells display characters in each of the registers as determined by the signal information, and these displayed characters can be sustained by means of separate A.C sources 250 connected between each electrode strip 420 and each of the associated electrodes 380 as described with respect to FIG. 10.

Display panels embodying the invention may also incorporate phosphor materials to provide display glow in different colors. For example, FIG. 15 shows a portion of a panel 400 which is panel 10 modified by the inclusion of a layer 243 of a phosphor material between the conductive film 180 and apertured plate 160. The remainder of the panel 400 includes all of the other features of panel 10. FIG. 16 shows a portion of a panel 500 which is panel 10 modified to include layer 243 of phosphor material between conductive film 180 and glass sheet 240. The layer 243 may comprise a selected phosphor powder dispersed in a carrier of a glass frit and a suitable binder. In addition, if the layer 243 has a relatively high dielectric constant of 5 or more due to the inclusion of a material such as barium titanate, then the glass plate 240 can be omitted in FIG. 16, and the phosphor layer will provide the desired insulation and capacitive effect between the electrodes 180 and 130 or 131.

Phosphor materials which may be used in practicing the invention are well known in the art, and one or more of these may be employed. A typical electroluminescent phosphor is ZnSzCu. Another desirable type of phosphor is a cathodoluminescent phosphor which is stimulated to glow by the applied signal and by electron bombardment. One such phosphor is ZnS:Mn,Sb,C1. Still another desirable type of phosphor is a photoelectroluminescent phosphor which is stimulated both by the applied signal and by radiation such as ultraviolet light. One such phosphor is ZnS:Mg,Cl.

In the various circuits described above and shown in the drawing, only sufficient circuitry is shown and described to illustrate the principles of operation. Circuit elements such as bias potentials, ground connections, current-limiting resistors and the like may not be shown, but those skilled in the art will be able to provide such circuit elements where needed, with no difficulty.

In general, too, the drawings are not intended to be dimensionally exact, and, in a typical display panel embodying the invention such as panel 10, the top plate 190 and bottom plate 20 are about one-quarter inch in thickness, and the plates 110 and 160 are about 40 mils in thickness. In addition, in plate 20, slots are 10 mils wide and mils deep, and electrodes are 5 mils in diameter. The cathodes are 36 mils wide and 1 to 3 mils thick. The holes 74 in cathodes 70 are I to 3 mils in diameter, and the holes in plate 110 and the holes 170 in plate are 18 to 24 mils in diameter and 40 mils deep. Electrodes 212 are about 3 mils in diameter.

It is clear that modifications may be made in the panels shown and described and in the modes of operation described. For example, although the panels as described are scanned from left to right, cell by cell or column by column, the scanning may be effected in other ways, with a suitable re-arrangement of parts and circuitry.

It is also to be noted that each of the panels described may be sealed inside an envelope so that, with respect to the panel itself. only a mechanical coupling of the various plates and electrodes would be required, and the seal around the edges of the panel could be omitted.

It is to be understood that the copending applications mentioned above are incorporated herein by reference. Those and other applications which are useful in operating and making display panels are also incorporated herein by reference, such applications including the following:

Application Ser. No. 764,983, filed Oct. 2, 1968, which describes and claims a method and apparatus for introducing mercury into a display panel.

Application Ser. No. 780,099, filed Nov. 12, 1968, which describes and claims a method and apparatus for obtaining memory in a display panel.

Application Ser. No. 881,024, filed Dec. 1, 1969, which describes and claims a method and apparatus for insuring the proper firing of cells at the beginning of a scanning cycle.

Application Ser. No. 881,660, filed Dec. 3, 1969, which describes and claims a method and apparatus for scanning a display panel, cell by cell, in any desired direction.

Application Ser. No. 850,841, filed Aug. 18, 1969, but abandoned in favor of application Ser. No. 8,773, filed Feb. 5, 1970, which describes and claims an arrangement for enhancing light output from a display panel.

What is claimed is:

1. A display device comprising a first gas cell,

first and second electrodes spaced apart and disposed within the gas in said first cell,

a second gas cell adjacent to and in gas communication with said first gas cell, and

a third electrode within the gas in said second cell and a fourth electrode insulated from said second cell and capacitively coupled thereto,

said first and second electrodes being operable to apply potential across said first cell and to produce glow in said first cell,

said third and fourth electrodes being operable to transfer glow from said first cell to said second cell and to sustain the glow therein by the capacitive coupling of signals thereto by way of said third and fourth electrodes.

2. The device defined in claim 1 wherein said second electrode is disposed between said first and second cells and said first and second cells communicate with each other through an aperture in said second electrode.

3. The device defined in claim 1 and including a third volume of gas disposed between said first and second gas cells, with said second and third electrodes being electrically coupled thereto.

4. The device defined in claim 1 wherein said fourth electrode comprises a transparent conductive film sepprated from said second gas cell by a glass film.

5. The device defined in claim 1 wherein said fourth electrode is separated from said second gas cell by an insulating phosphor sheet.

6. The device defined in claim 1 wherein said fourth electrode is insulated from and capacitively coupled to said second gas cell by an insulating plate consisting of phosphor material and an agent which imparts a relatively high dielectric constant to said plate.

7. The device defined in claim 1 and including circuit means for applying an alternating sustaining signal across said second gas cell and coupled to said third and fourth electrodes.

8. The device defined in claim 1 and including an electroluminescent phosphor layer associated with said second gas cell and including means for applying an energizing signal across said second gas cell and said phosphor layer to energize said second gas cell and said phosphor layer.

9. A device as defined in claim 1 wherein said fourth electrode is outside said second gas cell and is capacitively coupled thereto, and including a layer of electroluminescent phosphor material separating said fourth electrode from said second gas cell.

10. A display device comprising an array of a plurality of first gas cells disposed in rows and columns,

first and second electrodes spaced apart and disposed within the gas in each of said first cells,

an array of a plurality of second gas cells disposed in rows and columns and disposed adjacent to said first cells, each second cell being in gas communi cation with a first gas cell, and

a third electrode within the gas in each of said second cells and a fourth electrode means insulated from each said second cell and capacitively coupled thereto,

said first and second electrodes being selectively operable to apply potential across said first cells and to produce glow in said first cells,

said third and fourth electrodes being operable to transfer glow from one or more selected first cells to the associated second cells which are in gas communication therewith and to sustain the glow therein by the capacitive coupling of signals thereto by way of said third and fourth electrodes.

11. The device defined in claim 10 and including a third gas cell disposed between said first and second gas cells, with said second and third electrodes being electrically coupled thereto.

12. The device defined in claim 10 wherein said fourth electrode means comprises a transparent conductive film separated from said second cells by a glass film.

13. The device defined in claim 10 wherein said fourth electrode means is separated from said second cells by an insulating phosphor sheet.

14. The device defined in claim 10 wherein said fourth electrode means is insulated from and capacitively coupled to said second cells by an insulating plate comprising phosphor material and an agent which imparts a relatively high dielectric constant to said plate.

15. The device defined in claim 10 wherein said fourth electrode means comprises a transparent conductive film separated from said second cells by a glass film.

16. The device defined in claim 10 and including means for applying an alternating sustaining signal across said second cells.

17. The device defined in claim 10 and including an electroluminescent phosphor layer associated with said second cells and including means for applying an energizing signal across said second cells and said phosphor layer to energize said second cells and said phosphor layer.

18. A device as defined in claim 10 wherein said fourth electrode means is outside said second cells and is capacitively coupled thereto, and including a layer of electroluminescent phosphor material separating said fourth electrode means from said second cells.

19. A display panel comprising a gas-filled sandwich of elements including, in order,

a first insulating plate having an array of first electrodes in slots therein and an array of second electrodes spaced from said first electrodes but communicating therewith in the space therebetween defined by each slot, said first and second electrodes being oriented so that they are at an angle to each other and each second electrode crosses 13 V each first electrode, each crossing comprising a first gas cell, the first gas cells being arrayed in rows and columns, I I

said first and second electrodes being used to apply firing potentials to said first cells to fire each of said first cells in a selected order, I

a second insulating plate having a plurality of first apertures arrayed in rows and columns, each first aperture comprising a second gas cell, each second gas cell being aligned with and thus in gas communication with a first gas cell and witha'portion of a second electrode, r

third electrode means in operative relationwith said second gascells, I .f

a third insulating plate having. a plurality of second apertures arrayed in rows and columns, each second aperture comprising a third gas cell, each said third gas cell being aligned with and in gas communication with a second gas cell and with a portion of said third electrode means,

fourth electrode means remote from the gas filling in said cells and separated therefrom by an insulating layer and thus being capacitively coupled to each of said third gas cells,

said third and fourth electrodes being used to apply operating potentials to said third cells to transfer glow from a selected first cell to a selected third cell and to sustain glow in the selected third cells, and

a cover plate disposed over said third plate and said fourth electrode means and comprising a viewing plate for said panel.

20. The panel defined in claim 19 and including circuit means coupled to said first and second electrodes for turning on each of said first gas cells in turn, and circuit means coupled to said third andfourth electrodes for transferring flow from a selected first cell to a selected third cell and sustaining said glow in said third cell.

21. The panel defined in claim 19 and including circuit means coupled to said first and second electrodes for turning on each of said columns of first gas cells in turn, and circuit means coupled to said third and fourth electrodes for transferring glow from a selected first cell to a selected third cell and sustaining said glow in said third cell.

22. A display device comprising an array of first gas cells disposed in a common layer,

first and second electrodes in operative relation with each of said first cells for applying operating potentials thereto for selectively firing said first cells,

an array of second gas cells disposed in a common layer spaced from said array of first cells,

electrode means in operative relation with second cells for transferring glow from a selected first cell to a selected second cell which is in communication therewith,

said electrode means being operable to sustain glow in said selected second cells, and

auxiliary cells, each having two electrodes and disposed in a common layer between said first and second cells, there being a gas communication path from each first cell through an auxiliary cell to a second cell, said auxiliary cells serving as a buffer between said first cells and said second cells to prevent undesired interaction between said first and second cells when memory signals are applied to the electrode means'coupled to said second cells.

23. The device defined in claim 22 wherein said electrode means includes at least two electrodes coupled to each of said second cells.

24. The device defined in claim 22 wherein said electrode means includes at least two electrodes coupled to each of said second cells, one of said two electrodes being diposed in the gas in its cell and the other being insulated from the gas in its cell.

25. A display device comprising a gas-filled envelope including a plurality of first gas-filled cells arrayed in rows and columns,

first electrode means coupled to said first cells for scanning said cells sequentially, either row by row or column by column,

a plurality of second gas-filled cells arrayed in rows and columns spaced from said first cells, with each second cell being in gas communication with a first cell,

an electrode assembly coupled to said second cells including means for applying first signals for transferring glow out of selected ones of said first cells toward the corresponding second cells,

said electrode means also including means for applying second signals to said second cells for transferring said glow into said corresponding second cells and sustaining said glow in said second cells after said first signals have been removed.

26. A display device comprising a gas-filled envelope,

a first assembly in said envelope including a plurality of first gas-filled cells arrayed in rows and columns,

first electrode means coupled to said first assembly for receiving first signals for scanning said cells sequentially either row by row or column by column,

a second assembly is said envelope including a plurality of second gas-filled cells arrayed in rows and columns,

second electrode means and circuit means coupled to said second assembly for receiving (1) second signals for transferring glow from selected first cells to selected second cells to form a pattern of glowing cells in said second assembly, and (2) third signals of a different character than said first signals for maintaining said pattern of glowing cells in said second stratum after said second signals have been removed.

27. A display device comprising a plurality of first gas-filled cells arrayed in rows and columns for displaying a character made up of glowing selected cells,

first electrode means coupled to said first gas-filled cells for activating a selected pattern of such cells and then applying sustaining signals to said selected cells to sustain glow therein,

a plurality of second gas-filled cells arrayed in rows and columns and in communication with said first cells, and

said electrode means coupled to said second cells for scanning all of said second cells to provide a source of excited particles for said selected first cells.

28. The method of operating a display panel including first, second, third layers of cells, comprising the steps of scanning all the cells in said first layer of cells,

transferring glow from said first layer of cells through said second layer of cells to selected cells in said third layer of cells, and

sustaining the glow in said selected cells in said third layer of cells.

29. A display panel comprising:

a gas-filled envelope having a viewing windown and including;

a plurality of first gas-filled cells arrayed in rows and columns,

first electrode means coupled to each of said first cells for scanning and firing each of said cells sequentially, either row-by-row or column-bycolumn,

said first electrode means being diposed within the gas in each of said first cells,

a plurality of second gas-filled cells arrayed in rows and columns and spaced from said first cells, with each second cell being in gas communication with a first cell, and,

an electrode assembly coupled to said second cells including first electrode means within the gas in each of said second cells, and second electrode means insulated from the gas in each of said second cells,

said electrode assembly including means for applying first transfer signals thereto for transferring glow out of selected ones of said first cells to the corresponding second cells, and means for applying second memory signals to said second cells for sustaining said flow in said second cells after said first signals have been removed. 

1. A display device comprising a first gas cell, first and second electrodes spaced apart and disposed within the gas in said first cell, a second gas cell adjacent to and in gas communication with said first gas cell, and a third electrode within the gas in said second cell and a fourth electrode insulated from said second cell and capacitively coupled thereto, said first and second electrodes being operable to apply potential across said first cell and to produce glow in said first cell, said third and fourth electrodes being operable to transfer glow from said first cell to said second cell and to sustain the glow therein by the capacitive coupling of signals thereto by way of said third and fourth electrodes.
 2. The device defined in claim 1 wherein said second electrode is disposed between said first and second cells and said first and second cells communicate with each other through an aperture in said second electrode.
 3. The device defined in claim 1 and including a third volume of gas disposed between said first and second gas cells, with said second and third electrodes being electrically coupled thereto.
 4. The device defined in claim 1 wherein said fourth electrode comprises a transparent conductive film sepprated from said second gas cell by a glass film.
 5. The device defined in claim 1 wherein said fourth electrode is separated from said second gas cell by an insulating phosphor sheet.
 6. The device defined in claim 1 wherein said fourth electrode is insulated from and capacitively coupled to said second gas cell by an insulating plate consisting of phosphor material and an agent which imparts a relatively high dielectric constant to said plate.
 7. The device defined in claim 1 and including circuit means for applying an alternating sustaining signal across said second gas cell and coupled to said third and fourth electrodes.
 8. The device defined in claim 1 and including an electroluminescent phosphor layer associated with said second gas cell and including means for applying an energizing signal across said second gas cell and said phosphor layer to energize said second gas cell and said phosphor layer.
 9. A device as defined in claim 1 wherein said fourth electrode is outside said second gas cell and is capacitively coupled thereto, and including a layer of electroluminescent phosphor material separating said fourth electrode from said second gas cell.
 10. A display device comprising an array of a plurality of first gas cells disposed in rows and columns, first and second electrodes spaced apart and disposed within the gas in each of said first cells, an array of a plurality of second gas cells disposed in rows and columns and disposed adjacent to said first cells, each second cell being in gas communication with a first gas cell, and a third electrode within the gas in each of said second cells and a fourth electrode means insulated from each said second cell and capacitively coupled thereto, said first and second electrodes being selectively operable to apply potential across said first cells and to produce glow in said first cells, said third and fourth electrodes being operable to transfer glow from one or more selected first cells to the associated second cells which are in gas communication therewith and to sustain the glow therein by the capacitive coupling of signals thereto by way of said third and fourth electrodes.
 11. The device defined in claim 10 and including a third gas cell disposed between said first and second gas cells, with said second and third electrodes being electrically coupled thereto.
 12. The device defined in claim 10 wherein said fourth electrode means comprises a transparent conductive film separated from said second cells by a glass film.
 13. The device defined in claim 10 wherein said fourth electrode means is separated from said second cells by an insulating phosphor sheet.
 14. The device defined in claim 10 wherein said fourth electrode means is insulated from and capacitively coupled to said second cells by an insulating plate comprising phosphor material and an agent which imparts a relatively high dielectric constant to said plate.
 15. The device defined in claim 10 wherein said fourth electrode means comprises a transparent conductive film separated from said second cells by a glass film.
 16. The device defined in claim 10 and including means for applying an alternating sustaining signal across said second cells.
 17. The device defined in claim 10 and including an electroluminescent phosphor layer associated with said second cells and including means for applying an energizing signal across said second cells and said phosphor layer to energize said second cells and said phosphor layer.
 18. A device as defined in claim 10 wherein said fourth electrode means is outside said second cells and is capacitively coupled thereto, and including a layer of electroluminescent phosphor material separating said fourth electrode means from said second cells.
 19. A display panel comprising a gas-filled sandwich of elements including, in order, a first insulating plate having an array of first electrodes in slots therein and an array of second electrodes spaced from said first electrodes but communicating therewith in the space therebetween defined by each slot, said first and second electrodes being oriented so that they are at an angle to each other and each second electrode crosses each first electrode, each crossing comprising a first gas cell, the first gas cells being arrayed in rows and columns, said first and second electrodes being used to apply firing potentials to said first cells to fire each of said first cells in a selected order, a second insulating plate having a plurality of first apertures arrayed in rows and columns, each first aperture comprising a second gas cell, each second gas cell being aligned with and thus in gas communication with a first gas cell and with a portion of a second electrode, third electrode means in operative relation with said second gas cells, a third insulating plate having a plurality of second apertures arrayed in rows and columns, each second aperture comprising a third gas cell, each said third gas cell being aligned with and in gas communication with a second gas cell and with a portion of said third electrode means, fourth electrode means remote from the gas filling in said cells and separated therefrom by an insulating layer and thus being capacitively coupled to each of said third gas cells, said third and fourth electrodes being used to apply operating potentials to said third cells to transfer glow from a selected first cell to a selected third cell and to sustain glow in the selected third cells, and a cover plate disposed over said third plate and said fourth electrode means and comprising a viewing plate for said panel.
 20. The panel defined in claim 19 and including circuit means coupled to said first and second electrodes for turning on each of said first gas cells in turn, and circuit means coupled to said third and fourth electrodes for transferring flow from a selected first cell to a selected third cell and sustaining said glow in said thirD cell.
 21. The panel defined in claim 19 and including circuit means coupled to said first and second electrodes for turning on each of said columns of first gas cells in turn, and circuit means coupled to said third and fourth electrodes for transferring glow from a selected first cell to a selected third cell and sustaining said glow in said third cell.
 22. A display device comprising an array of first gas cells disposed in a common layer, first and second electrodes in operative relation with each of said first cells for applying operating potentials thereto for selectively firing said first cells, an array of second gas cells disposed in a common layer spaced from said array of first cells, electrode means in operative relation with second cells for transferring glow from a selected first cell to a selected second cell which is in communication therewith, said electrode means being operable to sustain glow in said selected second cells, and auxiliary cells, each having two electrodes and disposed in a common layer between said first and second cells, there being a gas communication path from each first cell through an auxiliary cell to a second cell, said auxiliary cells serving as a buffer between said first cells and said second cells to prevent undesired interaction between said first and second cells when memory signals are applied to the electrode means coupled to said second cells.
 23. The device defined in claim 22 wherein said electrode means includes at least two electrodes coupled to each of said second cells.
 24. The device defined in claim 22 wherein said electrode means includes at least two electrodes coupled to each of said second cells, one of said two electrodes being diposed in the gas in its cell and the other being insulated from the gas in its cell.
 25. A display device comprising a gas-filled envelope including a plurality of first gas-filled cells arrayed in rows and columns, first electrode means coupled to said first cells for scanning said cells sequentially, either row by row or column by column, a plurality of second gas-filled cells arrayed in rows and columns spaced from said first cells, with each second cell being in gas communication with a first cell, an electrode assembly coupled to said second cells including means for applying first signals for transferring glow out of selected ones of said first cells toward the corresponding second cells, said electrode means also including means for applying second signals to said second cells for transferring said glow into said corresponding second cells and sustaining said glow in said second cells after said first signals have been removed.
 26. A display device comprising a gas-filled envelope, a first assembly in said envelope including a plurality of first gas-filled cells arrayed in rows and columns, first electrode means coupled to said first assembly for receiving first signals for scanning said cells sequentially either row by row or column by column, a second assembly is said envelope including a plurality of second gas-filled cells arrayed in rows and columns, second electrode means and circuit means coupled to said second assembly for receiving (1) second signals for transferring glow from selected first cells to selected second cells to form a pattern of glowing cells in said second assembly, and (2) third signals of a different character than said first signals for maintaining said pattern of glowing cells in said second stratum after said second signals have been removed.
 27. A display device comprising a plurality of first gas-filled cells arrayed in rows and columns for displaying a character made up of glowing selected cells, first electrode means coupled to said first gas-filled cells for activating a selected pattern of such cells and then applying sustaining signals to said selected cells to sustain glow therein, a plurality of second gas-filled cells arrayed in rows and columns and in communication with said first cells, and said electrode means coupled to said second cells for scanning all of said second cells to provide a source of excited particles for said selected first cells.
 28. The method of operating a display panel including first, second, third layers of cells, comprising the steps of scanning all the cells in said first layer of cells, transferring glow from said first layer of cells through said second layer of cells to selected cells in said third layer of cells, and sustaining the glow in said selected cells in said third layer of cells.
 29. A display panel comprising: a gas-filled envelope having a viewing windown and including; a plurality of first gas-filled cells arrayed in rows and columns, first electrode means coupled to each of said first cells for scanning and firing each of said cells sequentially, either row-by-row or column-by-column, said first electrode means being diposed within the gas in each of said first cells, a plurality of second gas-filled cells arrayed in rows and columns and spaced from said first cells, with each second cell being in gas communication with a first cell, and, an electrode assembly coupled to said second cells including first electrode means within the gas in each of said second cells, and second electrode means insulated from the gas in each of said second cells, said electrode assembly including means for applying first transfer signals thereto for transferring glow out of selected ones of said first cells to the corresponding second cells, and means for applying second memory signals to said second cells for sustaining said flow in said second cells after said first signals have been removed. 